Ex Parte Brown

Patent Trial and Appeal Board

Aug 31, 2018

13632477 (P.T.A.B. Aug. 31, 2018)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR
13/632,477 10/01/2012 IanJ. Brown
37694 7590 09/05/2018
WOOD, HERRON & EV ANS, LLP (TOKYO ELECTRON)
2700 CAREW TOWER
441 VINE STREET
CINCINNATI, OH 45202
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www .uspto.gov
ATTORNEY DOCKET NO. CONFIRMATION NO.
SPST-OlOUSl 7557
EXAMINER
WHATLEY, KATELYNB
ART UNIT PAPER NUMBER
1714
NOTIFICATION DATE DELIVERY MODE
09/05/2018 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
usptodock@whe-law.com
twhite@whe-law.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte IAN J. BROWN
Appeal2017-009955
Application 13/632,477
Technology Center 1700
Before JEFFREY T. SMITH, JAMES C. HOUSEL, DONNA M. PRAISS,
Administrative Patent Judges.
PRAISS, Administrative Patent Judge.
DECISION ON APPEAL 1
STATEMENT OF THE CASE
Appellant2 appeals under 35 U.S.C. § 134(a) from the Examiner's
final decision to reject claims 1, 4, 10-12, 14, and 16.
We have jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.
1 In this decision, we refer to the Specification filed October 1, 2012
("Spec."), the Final Office Action entered June 24, 2016 ("Final Act."), the
Appeal Brief filed January 9, 2017 ("App. Br."), the Examiner's Answer
entered May 16, 2017 ("Ans."), and the Reply Brief filed July 17, 2017
("Reply Br.").
2 Appellant is the Applicant, Tokyo Electron Limited, which is also
identified as the real party in interest. App. Br. 3.
Appeal2017-009955
Application 13/632,477
The subject matter on appeal relates to methods for mixing chemicals
for use in semiconductor processing. Spec. ,r 2. According to the
Specification, resist coatings have been removed in semiconductor
manufacturing with a mixture of sulfuric acid and peroxide (SPM) in a batch
type processing mode. Id. ,r 3. The Specification explains that the industry
focus has switched from batch type processing to single wafer type
processes to address high defectivity associated with batch processing,
however, because single wafer SPM processes operate at higher
temperatures than batch processes, the resist strip time must be reduced to be
economically feasible. Id. ,r,r 3, 4. Claim 1 is illustrative (disputed matter
italicized):
1. A method of rapidly mixing process chemicals to
generate a high temperature sulfuric
acid and peroxide (SPM) treatment liquid for processing
a single substrate to remove a resist coating with a process time
of less than 2 minutes, the method comprising:
flowing a first process chemical that is sulfuric acid in a
process chemical delivery system from an inlet to an outlet
thereof with a direction of flow along a center axis;
injecting a second process chemical that is hydrogen
peroxide from a nozzle positioned downstream of the inlet and
into the flow of the first process chemical in the process
chemical delivery system to effect a mixing of the first process
chemical with the second process chemical to form the SPM
treatment liquid, which SPM treatment liquid includes reaction
products of the sulfuric acid and the hydrogen peroxide and has
a temperature of 170-220°C; and
dispensing the SP M treatment liquid at the temperature
of 170-220°Cfrom the outlet onto a portion of a surface of the
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Application 13/632,477
substrate and removing the resist coating within the process
time of less than 2 minutes,
wherein the nozzle is oriented at or near the center axis
and injection of the second process chemical is coaxial with the
center axis in an opposite direction to the direction of flow to
produce uniformity in the mixing of the first and second
process chemicals within a target mixing distance of 50 mm or
less between the nozzle and the outlet of the process chemical
delivery system and within a target mixing time of 2 ms or less,
thereby enabling the process time of less than 2 minutes.
App. Br. 16 (Claims Appendix).
The Examiner maintains and Appellant appeals the following
rejections under 35 U.S.C. § I03(a):
1. Claims 1, 4, 10, 14, and 16 over DeKraker3 in view of Walden4
and Trang. 5
2. Claim 11 over DeKraker in view of Walden and Trang as applied
to claim 10 and further in view of Lang. 6
3. Claim 12 over DeKraker in view of Walden and Trang as applied
to claim 1 and further in view of Hughes. 7
Ans. 2; App. Br. 4; Final Act. 3-10.
3 DeKraker et al., US 2010/0326477 Al, published Dec. 20, 2010
("De Kraker").
4 Walden, US 3,297,305, issued Jan. 10, 1967 ("Walden").
5 Trang et al., US 2009/0034361 Al, published Feb. 5, 2009 ("Trang").
6 Lang, US 4,869,595, issued Sept. 26, 1989 ("Lang").
7 Hughes et al., US 7,897,121 Bl, issued Mar. 1, 2011 ("Hughes").
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Application 13/632,477
OPINION
Rejection 1
The Examiner finds that claims 1, 4, 10, 14, and 16 are unpatentable
under 35 U.S.C. § 103(a) over DeKraker for the reasons stated on pages 3-7
of the Final Office Action.
Appellant argues the claims as a group. App. Br. 4--14. In
accordance with 37 C.F.R. § 4I.37(c)(l)(iv), claims 4, 10, 14, and 16 will
stand or fall together with independent claim 1.
Appellant argues that the Examiner erred in rejecting claim 1 because
DeKraker does not clearly teach dispensing the liquid sulfuric acid
composition at a temperature in the range of 130-200QC as the Examiner
finds. App. Br. 6. Appellant contends that even though paragraph 55 of
DeKraker states that the liquid sulfuric acid composition is dispensed at a
temperature about 130QC to about 200QC, this passage is nuanced and "must
be ... interpreted based on an understanding by a POSIT A of DeKraker as a
whole." Id. According to Appellant, paragraph 55 ofDeKraker does not
necessarily refer to SPM as the sulfuric acid composition because in two of
the three embodiments disclosed by DeKraker, the sulfuric acid composition
can only include sulfuric acid only, which is one interpretation of the
sulfuric acid composition provided in paragraph 28 of DeKraker. Id. at 7-8.
Appellant contends that a plausible understanding of paragraph 55 is that the
temperature ranges disclosed therein correspond, in order, to the three
embodiments for the timing of adding the hydrogen peroxide to the sulfuric
acid such that the third embodiment of dispensing sulfuric acid only into the
treatment chamber is the one that is dispensed at 130-200QC. Id. at 9-10.
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Application 13/632,477
Appellant also contends that DeKraker's disclosed examples use a
sulfuric acid temperature of 150QC mixed with room temperature peroxide
with no disclosure of the temperature of the resulting mixture and that the
temperature of the resulting mixture would be expected to drop below that of
the heated fluid. Id. at 10-12. Appellant further asserts that DeKraker is not
concerned with the mixing time in the delivery system because it uses a
three-component combination and teaches withholding the high temperature
component until just above the substrate surface in the treatment chamber.
Id. at 12-13. Appellant concedes that "Walden does disclose a counter-flow
injection to achieve complete admixture of two chemicals" and "Trang does
disclose overlapping distance dimensions," but contends that the additional
references do not address the deficiencies of DeKraker or suggest limiting
the mixing time in the delivery system. Id. at 12-14.
The Examiner responds that "liquid sulfuric acid composition" is
defined in paragraph 28 ofDeKraker to include SPM in addition to
explicitly disclosing that the liquid sulfuric acid composition can be mixed
before, during, or after dispensing, therefore paragraph 55 of DeKraker
teaches dispensing SPM treatment liquid at a temperature range of 130-
200QC, which overlaps the claimed range. Ans. 3. The Examiner also finds
that the temperature of dispensing is not considered critical or inventive in
Appellant's Specification. Id. (citing Spec. ,r 4). The Examiner further
responds that while DeKraker discloses applying a heated solution at the
substrate surface, it does not avoid the combination of heat, acid, and
peroxide upstream of the substrate surface. Id. at 4. The Examiner quotes
paragraphs 53 and 54, which disclose mixing the hydrogen peroxide with the
sulfuric acid prior to introduction into the treatment chamber, and paragraph
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Application 13/632,477
52, which describes the mixing of concentrated sulfuric acid with water-
containing hydrogen peroxide solution as a heat-generating exothermic
reaction that is "normally a significant source of heat." Id. at 4. The
Examiner further finds that DeKraker discloses adding water to the sulfuric
acid composition by condensation of water vapor into the composition to
allow larger temperature increases for a given amount of dilution and that
such water vapor is contacted with the liquid sulfuric acid prior to contacting
the surface of the substrate. Id. at 5 ( citing DeKraker ,r,r 46, 66). Thus, the
Examiner finds that DeKraker does not limit the presence of heat to after the
acid is injected from the delivery system as Appellant asserts since sulfuric
acid is mixed with hydrogen peroxide prior to injection from the delivery
system, the mixture generates heat, and the sulfuric acid composition is
provided at an elevated temperature. Id. (citing DeKraker ,r,r 35, 55, 52, 53)
Regarding optimizing the mixing distance or time in the delivery
system, the Examiner responds that the mixing distance and time would both
affect the reaction parameters and time in which heat is generated and that
DeKraker uses the energy created in the exothermic reaction of sulfuric acid
and hydrogen peroxide, plus steam to aid in the elevation of the liquid
temperature, therefore motivation exists to adjust the mixing distance or time
in the delivery system as DeKraker teaches high temperatures in the delivery
system. Id. at 5---6. The Examiner relies on Trang for teaching mixing
distance of chemicals affects the homogeneity and mixing time of the
chemicals, therefore, according to the Examiner, mixing distance and target
mixing time are result effective variables. Id. at 6.
Regarding the multiple embodiments disclosed by DeKraker, the
Examiner agrees with Appellant that an embodiment includes a liquid
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Application 13/632,477
sulfuric acid composition at the time of dispensing that includes hydrogen
peroxide and therefore is SPM. Id. at 8. Regarding the temperatures
disclosed in DeKraker's paragraph 55, the Examiner further responds that
because DeKraker includes an embodiment where hydrogen peroxide is
introduced before dispensing, the temperatures of paragraph 55 describe the
temperatures of the SPM solution. Id. The Examiner finds nothing in
DeKraker to suggest that the multiple embodiments have to correlate to
certain temperature embodiments described in paragraph 5 5 and further
finds that paragraph 55 teaches more than three temperature ranges,
including the open-ended ranges of at least 90QC and at least 130QC, which
both overlap with the range recited in claim 1. Id. at 10-11. The Examiner
also finds that if correlation of the temperatures is sequential with the
embodiments and the first embodiment is the mixing of hydrogen peroxide
with sulfuric acid before dispensing, then it correlates to the first
temperature range of at least 90QC, which overlaps the claimed range. Id. at
1 1.
The Examiner additionally finds that the temperature of dispensing is
not considered to be critical or inventive in Appellant's application because
it is only discussed in the background section. Id. at 12 ( citing Spec. ,r 4).
Regarding the teaching of DeKraker's paragraph 55, the Examiner also finds
that even if the temperature ranges disclosed therein are for sulfuric acid
only, one skilled in the art would have known that the addition of hydrogen
peroxide would raise the temperature due to the exothermic reaction
described by DeKraker. Id. at 15.
Regarding the mixing time, the Examiner finds Appellant's argument
that a skilled artisan would not be concerned about the mixing time unless
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Application 13/632,477
the hydrogen peroxide or high temperature components were missing in the
delivery system supports the Examiner's position that a skilled artisan would
know the mixing time is a result effective variable. Id. at 17. According to
the Examiner, mixing time is a result effective variable because it will affect
the homogeneity of the mixture that will be applied to the substrate. Id. at
21. The Examiner also finds that because the method taught by DeKraker,
Walden, and Trang is substantially similar to that claimed, the SPM applied
to the resist coating would be reasonably expected to remove the resist
coating within a process time of less than 2 minutes. Id. at 16-17.
In the Reply Brief, Appellant asserts that the Specification teaches
that temperature "is a critical and driving feature of the inventive method"
and that a high temperature of 170-220QC is an "underlying requirement of
the inventive method." Reply Br. 3. Appellant relies on paragraph 4 of the
Specification as support, which discloses temperature ranges, as well as
paragraphs 5-8 which discloses advantages and disadvantages of high
temperature, including the disadvantage of a shorter cleaning time of less
than 2 minutes for a single wafer SPM process. Id. at 2.
Appellant maintains that "DeKraker's invention is to limit the amount
of heat applied prior to dispensing onto the substrate, and to instead, provide
the high heat at or near the substrate surface via the addition of water
vapor." Id. at 3--4. Appellant contends that the Examiner's reliance on
paragraphs 28, 35, 52, and 55 of DeKraker for broadly teaching dispensing
of SPM at a high temperature is in error because the Examiner rejects
considering the prior art reference as a whole. Id. at 4. Appellant asserts
that the multiple meanings given "liquid sulfuric acid compositions" in
DeKraker requires a person having ordinary skill in the art to determine "the
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Application 13/632,477
correct meaning" based on the context in which the term is used and that the
temperature discussion in paragraph 35 would be understood to be relative to
the boiling point of water and the increase in temperature is accomplished by
the addition of water vapor. Id. at 4--5.
Paragraph 52, Appellant contends, must be interpreted in view of the
preceding paragraphs regarding limiting the water content of the liquid
sulfuric acid composition to no more than 5: 1 water to sulfuric acid molar
ratio, such that the addition of the water vapor is the primary source of heat
to allow large temperature increases for a given amount of dilution. Id. at 5.
Appellant also contends that paragraph 52 makes clear that the exothermic
reaction should not be a significant source of heat in their invention and
directs the adjustment of hydrogen peroxide addition to maximize the
sulfuric acid-water vapor reaction while providing sufficient oxidant for the
acid reaction. Id. Appellant further argues that the volatility/explosion
issues well-known to a skilled artisan for combining the chemicals in a
delivery line and allowing high temperatures and the exothermic reaction,
plus the conventional wisdom of adding room temperature hydrogen
peroxide slowly to the heated sulfuric acid to control the reaction, means
DeKraker's paragraph 55 "logically" refers to the higher temperature
applying to concentrated sulfuric acid only and not to the SPM mixture. Id.
at 6-7.
We are not persuaded by Appellant's arguments that the Examiner
reversibly erred in rejecting claim 1 under 35 U.S.C. § 103(a). Appellant
does not dispute that DeKraker discloses multiple embodiments for the
delivery of SPM treatment solution including combining sulfuric acid and
hydrogen peroxide before dispensing the SPM treatment liquid, nor does
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Application 13/632,477
Appellant dispute that DeKraker discloses dispensing at temperatures that
overlap the claimed temperature range, or that cleaning is fast at high
temperatures. Rather, Appellant urges that the disclosures of DeKraker
should be limited by "conventional wisdom" (Reply Br. 6) to dispensing at
the claimed high temperatures only when the solution is sulfuric acid only.
The difficulty with Appellant's argument is that, in a determination of
obviousness, a reference may be relied upon for all that it would have
reasonably suggested to one having ordinary skill in the art. Merck & Co. v.
Biocraft Labs., 874 F.2d 804, 807 (Fed. Cir. 1989) ("That the [prior art]
patent discloses a multitude of effective combinations does not render any
particular formulation less obvious."). Appellant does not dispute that
DeKraker' s disclosure encompasses the claimed combination of components
and conditions, but asserts that a skilled artisan would select the combination
where the claimed temperature is reached at dispensing only with sulfuric
acid alone or after dispensing only when the hydrogen peroxide is combined
with sulfuric acid and the supplemental heat is added via water vapor.
The Examiner's finding (Ans. 5) that DeKraker teaches both that the
sulfuric acid composition is provided at an elevated temperature and that
sulfuric acid can be mixed with hydrogen peroxide, which would generate
additional heat, prior to the injection from the delivery system, is supported
by the record. DeKraker ,r,r 35, 52, 53, 55. The Examiner's finding that
Trang discloses mixing distance of chemicals effects the homogeneity and
mixing time (Ans. 6; Final Act. 4--5) is also supported by the record and not
disputed by Appellant. Trang ,r,r 39, 43. Based on these findings, the
Examiner reasonably determines (Ans. 6) that a skilled artisan would have
motivation to adjust the mixing distance or time in the delivery since mixing
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Application 13/632,477
distance and target mixing time are result effective variables that effect the
reaction parameters and time that heat is generated. Therefore, the
combination of the teachings from DeKraker and Trang, together with
Walden's teaching that orienting a nozzle at the center axis and injecting a
second chemical liquid coaxial with the center axis in a direction opposite
the direction of flow for efficient mixing of fluids (Final Act. 4; Walden
2:21-37, Figs. 1, 3), reasonably suggests the claimed method to one having
ordinary skill in the art. Merck, 874 F.2d at 807.
In sum, we affirm the Examiner's rejection of claim 1 as well as
claims 4, 10, 14, and 16 as obvious over DeKraker in view of Walden and
Trang.
Re} ections 2 and 3
The Examiner finds that claims 11 and 12 are unpatentable under 35
U.S.C. § 103(a) over DeKraker in view of secondary references for the
reasons stated on pages 7-10 of the Final Office Action.
Appellant argues that the Examiner erred in rejecting claims 11 and
12, which indirectly depend from claim 1, for the same reasons discussed
above in connection with Rejection 1. Appellant further contends that the
secondary references relied upon by the Examiner do not cure the
deficiencies of DeKraker in view of Walden and Trang as applied to claims
land 10.
Because we do not find Appellant's arguments persuasive of error in
the rejection of claims 1 and 10 for the reasons discussed above in
connection with Rejection 1, we likewise are not persuaded that the
Examiner erred in rejecting claims 11 and 12.
In sum, we affirm the Examiner's rejections of claims 11 and 12.
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Conclusion
For the above reasons, we affirm the Examiner's rejections under 35
U.S.C. § 103 of claims 1, 4, 10-12, 14, and 16.
DECISION
The Examiner's decision is affirmed.
No time period for taking any subsequent action in connection with
this appeal maybe extended under 37 C.F.R. § 1.136(a)(l).
AFFIRMED
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